1. Fluid and Electrolyte Management in the Pediatric Surgical Patient Dr. Wilma Albulario Baltazar, FPCS

2. Management of Fluids and Electrolytes Long been defined and qualified Long been defined and qualified Not the Case Not the Case - mismanagement of fluids and electrolytes  morbidity and death - mismanagement of fluids and electrolytes  morbidity and death - failure to resuscitate young patients from hypovolemic deficiency states  multi systemic failure  demise - failure to resuscitate young patients from hypovolemic deficiency states  multi systemic failure  demise - inappropriate over-hydration of the young infant during the stresses of anesthesia and surgery  produce interstitial fluid shifts and pulmonary edema  respiratory difficulties - inappropriate over-hydration of the young infant during the stresses of anesthesia and surgery  produce interstitial fluid shifts and pulmonary edema  respiratory difficulties

3. Essential that Surgeons Assess the Fluid Needs of the Pediatric Patient Throughout the Entire Period of Surgical Management Pre-operative resuscitation phase Pre-operative resuscitation phase During intra-operative management During intra-operative management Throughout the post-operative recovery phase Throughout the post-operative recovery phase Patient has regained the normovolemic state Patient has regained the normovolemic state  baseline maintenance fluid requirements  baseline maintenance fluid requirements

4. Assessment must take account of Volume requirement Volume requirement Rate of administration and resuscitation Rate of administration and resuscitation Composition of the fluid with regard to electrolyte, osmotic Composition of the fluid with regard to electrolyte, osmotic and colloid requirements and colloid requirements Need for additional oxygen carrying capacity and clotting factors Need for additional oxygen carrying capacity and clotting factors AIM: To give appropriate choice of fluids

5. Thorough understanding of the role of regulatory factors Renin-Angiotensin mechanism Renin-Angiotensin mechanism Anti-diuretic hormones Anti-diuretic hormones essential essential Development of an intelligent fluid and electrolyte program Development of an intelligent fluid and electrolyte program

6. Maintenance Fluid Requirements Replacement of insensible losses Replacement of insensible losses Common practice in adults of restricting oral intake after midnight the night before surgery - can in the neonate and young infant result in delivery in the operating room of a patient who has been significantly FLUID RESTRICTED FOR AS MUCH AS HALF A DAY  SIGNIFICANT DEHYDRATION - can in the neonate and young infant result in delivery in the operating room of a patient who has been significantly FLUID RESTRICTED FOR AS MUCH AS HALF A DAY  SIGNIFICANT DEHYDRATION

7. Maintenance Fluid Requirements Infants require no more than 3 to 4 hours to empty their stomach of clear liquids Infants require no more than 3 to 4 hours to empty their stomach of clear liquids Careful planning is important Careful planning is important - infants are awakened and given a clear liquid oral - infants are awakened and given a clear liquid oral feeding 3 hours before surgery feeding 3 hours before surgery - infants are scheduled as first cases in the morning - infants are scheduled as first cases in the morning

8. Maintenance Fluid Requirement Overhydration of infants during a short operation procedure - Rapid administration of dilute maintenance type - Rapid administration of dilute maintenance type solutions to a slightly dehydrated patient  lead to solutions to a slightly dehydrated patient  lead to retention of large volumes of diluted electrolyte solutions retention of large volumes of diluted electrolyte solutions or dextrose and water  shifts of this fluid to the or dextrose and water  shifts of this fluid to the interstitial tissue (lungs) interstitial tissue (lungs)

9. Maintenance Fluid Requirement For pediatric patients undergoing a procedure with little anticipated blood loss, in which the peritonial cavity is not significantly invaded and in which the disease produces neither inflammation, edema nor ascites Fluid administration should consist primarily of replacing insensible losses Fluid administration should consist primarily of replacing insensible losses

10. Maintenance Fluid Requirement Insensible or Maintenance Requirements in infants and children in 24 hours 100ml/kg up to 10kg 100ml/kg up to 10kg 50ml/kg from 11-20kg 50ml/kg from 11-20kg 20ml/kg beyond 20kg 20ml/kg beyond 20kg A second formula that approximates the first over a wide range of sizes and ages (100ml – 3 x age [years]) x weight (kg) (100ml – 3 x age [years]) x weight (kg)

11. Maintenance Fluid Requirement The recommended maintenance fluid requirements on an hourly basis can be extrapolated from the Holiday-Segar method. Holiday and Segar estimated that 100ml of water is lost burning 100 calories per day for a 10kg child and this translates to 1000ml/24 hours or approximately 4ml/kg/hour Holiday-Segar method. Holiday and Segar estimated that 100ml of water is lost burning 100 calories per day for a 10kg child and this translates to 1000ml/24 hours or approximately 4ml/kg/hour Hourly Maintenance Fluid Requirements Hourly Maintenance Fluid Requirements Weight (kg) Fluid Fluid <104ml/kg/hr 10-20 40 + 2 ml for each kg above 10 kg >20 60 + 1 ml for each kg above 20kg

12. Electrolytes can be defined for this infant by a formula which states that the need for sodium, chloride and potassium is equal to 3 mEq/kg/24 hours Electrolytes can be defined for this infant by a formula which states that the need for sodium, chloride and potassium is equal to 3 mEq/kg/24 hours By adding 3 mEq/kg to 100ml/kg free-water requirements for the infant  we would produce a solution equivalent to 1/5 (20%) normal saline By adding 3 mEq/kg to 100ml/kg free-water requirements for the infant  we would produce a solution equivalent to 1/5 (20%) normal saline NSS has 154 mEq/L or 15.4 mEq/dL NSS has 154 mEq/L or 15.4 mEq/dL 1/5 NSS has 3 mEq/dL (D5 0.22 NaCl) 1/5 NSS has 3 mEq/dL (D5 0.22 NaCl) Maintenance Fluid Requirement

13. Fluids that are lost directly from the body in volumes significant enough to be collected and measured Fluids that are lost directly from the body in volumes significant enough to be collected and measured They can be directly measured therefore they can be replaced volume for volume They can be directly measured therefore they can be replaced volume for volume The composition of such fluid varies depending on whether it is primarily gastric aspirate or fluid from beyond The composition of such fluid varies depending on whether it is primarily gastric aspirate or fluid from beyond Measured Losses

14. Composition of Gastro-intestinal fluids (mEq/L) Composition of Gastro-intestinal fluids (mEq/L) Fluid FluidNaKClHCO3 Saliva 10 10 26 26 10 10 30 30 Gastric 60 60 10 10130 Small Intestines 140 5100 30 30 Large Intestines 60 60 30 30 40 40

15. Composition of the different intravenous fluids (in mmol/L except for detrose) SolutionNaClKMgCa HCO3 from HCO3 from Dextrose % AcetateGluconateLactate 0.9 NSS 154154 0.45 NaCl 7777 D 2.5 0.45 NaCl 77772.5 D 5 0.45 NaCl 77775 D 5 0.3 NaCl 51515 D 5 0.22 Nacl 38385 D 5 LR 13010941.5285 D 5 NR 1409851.527235 D 5 NM 4040131.5165 D 5 IMB 2522201.5235 Plasmalyte 56 in D 5% 4040131.516 Plasmalyte1409851.52723 SPPS II 14010251.150.75282 Hartmann’s solution in D 5% 13011051305

16. Measured Losses Solution for replacing losses of gastric secretions Gastric Juice Replacement Fluid (mEq/L) D 5 0.45 NaCl + 30 mEq KCL/L Na 60 – 75 77 Cl 105 – 130 107 K 5 – 10 30 H - 0 – 65 0

17. Measured Losses Losses beyond the pylorus - essentially ultrafiltrates of the plasma or serum - essentially ultrafiltrates of the plasma or serum - best replaced by balanced salt solutions such as lactated Ringer’s solution (D 5 LR) - best replaced by balanced salt solutions such as lactated Ringer’s solution (D 5 LR)

18. Measured Losses Timely replacement of these measurable losses at least on an every 4 hour schedule should be done Timely replacement of these measurable losses at least on an every 4 hour schedule should be done

19. HYPOVOLEMIA is the most common cause of shock in children worldwide HYPOVOLEMIA is the most common cause of shock in children worldwide

20. Resuscitation from Hypovolemia Hypovolemic State - losses beyond the standard insensible losses - losses beyond the standard insensible losses - measurable losses of body fluids that have not been replaced in a timely fashion - measurable losses of body fluids that have not been replaced in a timely fashion Results in decrease circulatory volume  underperfusion of body tissues  ischemia  damage to vital tissues decrease circulatory volume  underperfusion of body tissues  ischemia  damage to vital tissues

21. Estimation of Blood Loss in Childhood Hemorrhagic Shock Stage Stage 1234 Blood Loss (%) <1515-2025-40>40 Cap refill (sec) ≤2>2>5>5 SensoriumNormalIrritableLethargyUnresponsive Heart Rate NormalIncreasedIncreased± Pulse Pressure NormalNormal/DecreasedDecreasedDecreased Systolic Blood Pressure NormalNormalNormal/DecreasedDecreased Urinary Output NormalNormal/DecreasedDecreasedAbsent

22. Resuscitation from Hypovolemia Fluid Volumes - 20ml/kg boluses over 20 minutes - If severe shock, 20ml/kg over 5 to 10 minutes - Consider smaller volumes, 10ml/kg, if cardiogenic schock suspected - Repeat as needed to a total volume of 60 ml/kg

23. Resuscitation from Hypovolemia Crystalloids Probably best achieved with crystalloids Probably best achieved with crystalloids Types Types Normal saline Normal saline Ringer’s lactate Ringer’s lactate Benefits Benefits Inexpensive Inexpensive Readily available Readily available Do not produce sensitivity reactions Do not produce sensitivity reactions Expand interstitial space/restore sodium deficits Expand interstitial space/restore sodium deficits Drawbacks Drawbacks Rapidly redistributes to extravascular space Rapidly redistributes to extravascular space Large quantity may be required to restore deficit Large quantity may be required to restore deficit Potential for pulmonary edema in child with pulmonary or cardiac disease Potential for pulmonary edema in child with pulmonary or cardiac disease

24. Resuscitation from Hypovolemia Colloids Remain in intravascular compartment for hours longer than crystalloids Remain in intravascular compartment for hours longer than crystalloids Types Types 5% Albumin 5% Albumin Fresh frozen plasma Fresh frozen plasma Synthetic colloid solutions Synthetic colloid solutions Drawbacks Drawbacks Sensitivity reactions Sensitivity reactions Perhaps higher risk of pulmonary edema Perhaps higher risk of pulmonary edema

25. Blood Products PRBCs generally recommended in trauma patients when signs of shock or hemodynamic instability persist despite 40-60 ml/kg of isotonic crystalloids PRBCs generally recommended in trauma patients when signs of shock or hemodynamic instability persist despite 40-60 ml/kg of isotonic crystalloids Administer 10-15 ml/kg Administer 10-15 ml/kg Resuscitation from Hypovolemia

26. Reestablishment of circulatory dynamics is heralded by production of Reestablishment of circulatory dynamics is heralded by production of sustained adequate urinary output sustained adequate urinary output Resuscitation from Hypovolemia

27. Intraoperative Fluid Administration During the operative procedure Fluid of choice should be that of the most dominant fluid loss Fluid of choice should be that of the most dominant fluid loss ex. 1. Elective procedure – herniotomy ex. 1. Elective procedure – herniotomy - insensible loss is the dominant fluid deficit - insensible loss is the dominant fluid deficit - replacement with hypotonic fluids should be given to replace free water and minimal electrolytes - replacement with hypotonic fluids should be given to replace free water and minimal electrolytes ex. 2. Procedures in which there is significant major, prolonged invasion of the abdominal and thoracic cavity ex. 2. Procedures in which there is significant major, prolonged invasion of the abdominal and thoracic cavity - replacement with balanced salt or blood products variety should be chosen - replacement with balanced salt or blood products variety should be chosen

28. Intraoperative Fluid Administration Volume restoration should be based on - assessment of the preoperative volume restoration rate - assessment of the preoperative volume restoration rate - Intraoperative and postoperative fluid requirements

29. Intraoperative Fluid Administration In assessing fluid needs after surgery - it is important to calculate the volume and electrolyte concentration of all intravenous infusions administered intraoperatively by the anesthesiologist - it is important to calculate the volume and electrolyte concentration of all intravenous infusions administered intraoperatively by the anesthesiologist - adjustments have to be made in the postoperative fluid orders to avoid FLUID OVERLOAD or HYPERTONICITY - adjustments have to be made in the postoperative fluid orders to avoid FLUID OVERLOAD or HYPERTONICITY

30. Intraoperative Fluid Administration Blood chemistry measurements should be obtained immediately after surgery to identify any gross distortion of electrolyte pattern and to write the first fluid orders Reassessment of electrolytes and rewriting of fluid orders may need to be done 3 or 4 times in the first 24 hours

31. Scientific Basis for the Fluid and Electrolyte Program Rational fluid administration program for postoperative and post-trauma pediatric patients is based on - calculation of insensible losses - calculation of insensible losses - measurement of external losses - measurement of external losses - a reasoned estimation of fluids required to restore third-space shifts - a reasoned estimation of fluids required to restore third-space shifts - careful monitoring of urine output - careful monitoring of urine output

32. Scientific Basis for the Fluid and Electrolyte Program Estimating intraoperative and postoperative third-space requirements Third-space shifting occurs when - fluids shift from the vascular space to the extra-vascular space when there is ischemic damage to the capillaries - fluids shift from the vascular space to the extra-vascular space when there is ischemic damage to the capillaries - osmotic imbalances are created, as when there is inflammation of tissues, resulting in leakage of albumin into the extravascular space - osmotic imbalances are created, as when there is inflammation of tissues, resulting in leakage of albumin into the extravascular space - when there is obstruction of the sinusoidal capillary system in the liver resulting in ascites

33. Scientific Basis for the Fluid and Electrolyte Program Edema or Ascitis and any shift of fluid into the bowel lumen or wall in obstructive or inflammatory states represents THIRD-SPACE SHIFTS THIRD-SPACE SHIFTS These fluid volumes cannot be measured. Only estimated.

34. Scientific Basis for the Fluid and Electrolyte Program Abdominal cavity - Divided into quadrants - An additional volume of osmotically active solutions will be required that is equal to ¼ the maintenance volume for each quadrant that is affected by either an obstruction or inflammatory disease or a surgical intervention

35. Scientific Basis for the Fluid and Electrolyte Program Ex. 1 Simple appendicitis - at most 2 quadrants or ½ of the maintenance volume has to be added (disease affects 1 quadrant and the surgeon affects 1 quadrant) - at most 2 quadrants or ½ of the maintenance volume has to be added (disease affects 1 quadrant and the surgeon affects 1 quadrant) Ex. 2 If the disease affects the entire peritonial cavity in ruptured appendicitis with generalized peritonitis (4 quadrants) and the surgeon explores the entire abdominal cavity (4 quadrants) - 2 times maintenance volume in the form of balanced salt solution or a more active osmotic solution (red cells, plasma) has to be added to the calculated maintenance and the measured ongoing losses. - 2 times maintenance volume in the form of balanced salt solution or a more active osmotic solution (red cells, plasma) has to be added to the calculated maintenance and the measured ongoing losses.

36. Scientific Basis for the Fluid and Electrolyte Program Important to realize that the third-space volume is just a “guess” - careful monitoring and adjustments in the rate of fluid administration are essential to provide the patient with adequate volume restoration in a timely fashion - careful monitoring and adjustments in the rate of fluid administration are essential to provide the patient with adequate volume restoration in a timely fashion

37. Scientific Basis for the Fluid and Electrolyte Program Guide for volume calculation in surgical pediatric patients Correction of prior deficits Correction of prior deficits - 10-20 ml/kg crystalloid bolus up to 3 times - 10-20 ml/kg crystalloid bolus up to 3 times Normal requirements Normal requirements - first 10 kg 100ml/kg/day - first 10 kg 100ml/kg/day - second 10 kg plus 50ml/kg/day - second 10 kg plus 50ml/kg/day - each additional kg plus 20ml/kg/day - each additional kg plus 20ml/kg/day Replacement of losses Replacement of losses - volume per volume replacement of measured external abdominal losses - volume per volume replacement of measured external abdominal losses - third-space losses - third-space losses * quadrant rule for abdomen * quadrant rule for abdomen - additional ¼ of calculated maintenance for every affected - additional ¼ of calculated maintenance for every affected quadrant quadrant

38. Sample Case A 4 year old, 20kg child has had several days of crampy abdominal pain. For the last 2 days, he has been vomiting repeatedly and the vomitus is greenish. He has fever of 38 o – 39 o C. His urine output has dropped significantly. On physical exam, the abdomen is tense and tender with guarding throughout. He was thought to have a ruptured appendix. He was hydrated with lactated Ringer’s solution until his urine output came up to 38ml/hr for 2hours. He was then taken to the OR and his abdomen explored. A ruptured Meckle’s diverticulum with inflammatory adhesions of bowel loops and a high grade distal partial small intestinal obstruction was seen. The diverticulum was wedged out, transverse closure of the bowel, inflammatory adhesions were taken down and the peritoneal cavity was lavaged with warm saline. Appendectomy was performed.

39. Interactive Question 1. What would be this child’s total fluid requirement for the 24 hours following surgery assuming he had 100 ml of loss through his naso-gastric tube before and after his operation? a. 3000 ml a. 3000 ml b. 4600 ml b. 4600 ml c. 1500 ml c. 1500 ml d. 2100 ml d. 2100 ml

40. Sample Case Calculate his 24 hour volume requirement Maintenance fluid requirement Maintenance fluid requirement 100ml/kg to 10kg and 50ml/kg to 20kg 100ml/kg to 10kg and 50ml/kg to 20kg = 1500ml as D 5 0.22NSS with 20-30mEq KCL/L = 1500ml as D 5 0.22NSS with 20-30mEq KCL/L Measured Losses Measured Losses assuming he had 100ml of loss through his naso-gastric tube before and after his operation assuming he had 100ml of loss through his naso-gastric tube before and after his operation = 100ml as D 5 0.45NSS +30mEq KCL/L = 100ml as D 5 0.45NSS +30mEq KCL/L Third-space Loss Third-space Loss Applying the quadrant scheme Generalized peritonitis – four quadrants – one additional maintenance volume as D 5 LR – 1500 ml General Exploration of whole abdomen – four quadrants – one additional maintenance volume as D 5 LR – 1500 ml

41. Sample Case Total fluid administration for 24 hours following surgery Volume restitution 3,000ml of D 5 LR Volume restitution 3,000ml of D 5 LR Maintenance fluid 1,500ml of D 5 0.22 NSS + 3mEq KCL Maintenance fluid 1,500ml of D 5 0.22 NSS + 3mEq KCL Measured loss 100ml of D 5 0.45 NSS + 3mEq KCL Measured loss 100ml of D 5 0.45 NSS + 3mEq KCL Total 4,600ml in 24 hours= 190 ml/hr Total 4,600ml in 24 hours= 190 ml/hr

42. Interactive Question 2. What would be considered as adequate urine output for this patient? a. 15 ml/hour b. 30 ml/hour c. 10 ml/hour d. 5 ml/hour

43. Scientific Basis for the Fluid and Electrolyte Program Urine output and concentration - the 2 most helpful guides to fluid management of the pediatric patient - the 2 most helpful guides to fluid management of the pediatric patient Range of urine concentration and output in neonatal surgical patients Range Osmolality (mOsm/kg) 67-582 Specific Gravity 1.002-1.040 Urine output (ml/kg/hour) 1.5 – 2

44. Sample Case Administer 190 ml of D5LR/hour monitor urine output monitor urine output - if < 30 ml/hour – increase rate of volume administration - if < 30 ml/hour – increase rate of volume administration - if > 40 ml/hour – decrease rate of volume administration - if > 40 ml/hour – decrease rate of volume administration after 3 hours of 190 ml/hour of D5LR after 3 hours of 190 ml/hour of D5LR - urine output was averaging 50 ml/hour - urine output was averaging 50 ml/hour - so fluid administration rate was slowed to 150 ml/hour - so fluid administration rate was slowed to 150 ml/hour - urine output came down to 38 ml/hour - urine output came down to 38 ml/hour 190 ml of D5LR were run for 3 hours ~ 570ml 190 ml of D5LR were run for 3 hours ~ 570ml 150 ml of D5LR were run for 3 hours ~ 450ml 150 ml of D5LR were run for 3 hours ~ 450ml Total fluid run for 6 hours 1020ml Total fluid run for 6 hours 1020ml

45. Sample Case 18 hours remaining during which to give - maintenance fluid - D5.22NSS + KCL – 1500 ml - maintenance fluid - D5.22NSS + KCL – 1500 ml - NGT losses - D5.45NSS + KCL - 100 ml - NGT losses - D5.45NSS + KCL - 100 ml 1600 ml 1600 ml - additional D5LR required to maintain a rate of 150 ml/hour for 18 hrs - additional D5LR required to maintain a rate of 150 ml/hour for 18 hrs 150 ml x 18 hours = 2700 ml 150 ml x 18 hours = 2700 ml - 1600 ml - 1600 ml 1100 ml of D5LR 1100 ml of D5LR Initial “guess” for 3 rd space loss was 3000 Initial “guess” for 3 rd space loss was 3000 Actual fluids used for 3rd space loss - Actual fluids used for 3rd space loss - (1100 + 1020) = 2120 (1100 + 1020) = 2120 “guess” was off by 880 “guess” was off by 880

46. Interactive Question 3. Will you use D5LR to replace the total fluid requirement of this baby? A. Yes B. No

47. Sample Case We can use balance salt solution exclusively during the first 24 hours after the operation. We could then adjust the rate of fluid administration until it is down to 65 ml/hour (the rate required to administer maintenance fluid) At this point, the patient should be switched to D5.22NSS with added K for his maintenance fluid

48. Sample Case Consequences of continued administration of isotonic electronic solution - result in raising serum osmolality in the form of hypertonic sodium and chloride balances - result in raising serum osmolality in the form of hypertonic sodium and chloride balances eventual secretion of ADH eventual secretion of ADH - failure to recognize this would lead to the inaccurate conclusion that the patient is again hypovolemic and if corrected by additional volume of osmotically active solution, the situation will be worsened patient becomes more hyper osmolar and continues to secrete ADH and retain fluid resulting in fluid overload pulmonary edema - failure to recognize this would lead to the inaccurate conclusion that the patient is again hypovolemic and if corrected by additional volume of osmotically active solution, the situation will be worsened patient becomes more hyper osmolar and continues to secrete ADH and retain fluid resulting in fluid overload pulmonary edema

49. Sample Case He can be extracted from such a state only by volume restriction and administration at maintenance rates of D5water this allows the slow excretion of his excess electrolytes and the appropriate replacement thereof with water, bringing him back to balance

50. Dear God, Please let them get it right the first time…